Yarn feeding device for textile machines such as knitting machines and the like

ABSTRACT

A yarn feed device for a textile machine such as a knitting machine, the device being capable of feeding yarn over a range of feed rates and comprising a plane surface rotatable about an axis normal to the surface, a conical roller which is rotatable about an axis inclined to the surface and cooperating with the plane surface to define a nip, a drive for rotating the surface or the roller and a yarn guide adjustable to supply yar to the nip at different points along the nip, the yarn thereby being given a speed corresponding to the linear speed of the plane surface at the point of supply.

United States Patent 11 1 A Smith et a1.

1 1 YARN FEEDING DEVICE FOR TEXTILE MACHINES SUCH AS KNITTING MACHINESAND THE LIKE [75] Inventors: Donald Smith; John Michael Shepherd, bothof llltlcy. England [73] Assignee: I.W.S. Nominee Company Limited,London. England 221 Filed: Aug. 21. 1973 211 App]. 190.; 390,197

Related US. Application Data [63] Continuation-impart of Ser. No.166.134. July 26.

1971, abandoned.

130] Foreign Application Priority Data July 29, 1970 Great Britain36773/70 [52] US. Cl. 226/184, 66/132 R [51] Int. Cl D04b 15/48 [58]Field of Search 66/132 R, 132 T; 226/184; 74/532, 194

[56] References Cited UNITED STATES PATENTS 9/1915 Boal..... 1. 74/5325/1925 Willis r 74/532 X 7/1938 Lindley .1 66/132 R 1 1 Jan. 28, 1975Primary Examiner-Robert R. Mackey Attorney, Agent. or Firm-Cameron.Kerkam. Sutton.

'Stowell & Stowell 571 ABSTRACT A yarn feed device for a textile machinesuch as a knitting machine, the device being capable of feeding yarnover a range of feed rates and comprising a plane surface rotatableabout an axis normal to the surface, a conical roller which is rotatableabout an axis inclined to the surface and cooperating with the planesurface to define a nip, a drive for rotating the surface or the rollerand a yarn guide adjustable to supply yar to the nip at different pointsalong the nip, the yarn thereby being given a speed corresponding to thelinear speed of the plane surface at the point of supply.

3 Claims, 4 Drawing Figures YARN FEEDING DEVICE FOR TEXTILE MACHINESSUCH AS KNITTING MACHINES AND THE LIKE This application is acontinuation-in-part of our application Ser. No. 166,134 filed July 26,1971, now abandoned.

BACKGROUND OF THE INVENTION An increasing number ofjersey fabrics areknitted on circular machines and many of these machines nowadays arefitted with positive feed devices which feed yarn to the needles at acontrolled rate. With the adoption of positive feeding, the loop length,which is the basic parameter of fabric quality and dimensions, becomesessentially independent of all other variables including yarn tension,yarn friction and machine cam setting. Furthermore, the current tendencyis towards fine fabrics which require finer yarns and as a consequencethe possibility of yarn break is much higher and the need for positivefeed much greater.

The number of feed points on a multifeed circular knitting machine,which correspond to the number of courses knitted on the machine at anyone time, range from 1 to 48 or more. Normally, they have 36 or 48 feedpoints.

One of the most widely used positive feed devices comprises a drivenendless belt which is wrapped around a series of freely rotatable drums,one drum for each feed point on the knitting machine. Yarn is passedbetween the driven belt and the drum and is fed to the needles at aspeed equal to the belt speed. The belt speed can be varied but it isthe same for each feed point. In setting up the machine it would bepreferable to be able to individually alter the feed speed for each feedpoint, but with this type of positive feed it is impossible and has tobe achieved by other means, e.g. by adjustment of the cam setting.

Only the simplest fabric structures, for example, interlock and simpleribs, can be knitted with a single yarn speed. Other fabrics, forexample Ponti-di-Roma and piques, require two or more yarn speeds. Tocope with this situation machines are provided with banks of I drumsabove each feed point, each drum being capable of being driven at adifferent rate from the endless belt on that particular level. Inpractice, however, there is room for at most four drums above each feedpoint and usually only two or three. While these do provide a variationin the number of feed rates at which yarn can be fed to the needles,they produce a very limited pattern range and cannot be used on machinesemploying a Jacquard mechanism. Normally, Jacquard knitting machinesrequire such a large range of feed rates that positive feedarrangements, though very desirable, are not available and cannottherefore be used THE PRESENT INVENTION A yarn feed device has now beendeveloped which is capable of feeding yarn over a wide range of feedrates and is suitable for use on a knitting machine employing a Jacquardmechanism as well as on many other knitting machines.

According to the invention, a yarn feed device for a I textile machinecomprises a plane surface rotatable about an axis normal to the surface,a conical roller which is rotatable about an axis inclined to thesurface and cooperates with the plane surface to define a nip, a drivefor rotating the surface or the roller (or both,

if identical surface speeds at the nip can be ensured) and a yarn guidearranged to supply yarn to the nip at a selected point along the nipwhereby the yarn is given a speed corresponding to the linear speed ofthe plane surface at the point of supply.

The plane surface is most conveniently in the form of a disc rotatableabout its central axis. The conical roller may have the form of either acomplete or a truncated cone, but it will be appreciated that theconical form must be regular with respect to the axis of rotation of theroller. The inclination and disposition of such axis in relation to theaxis of rotation of the plane surface must be such as to ensuresubstantial correspondence of the linear speeds of the plane surface andthe conical roller along the length of the nip.

A wide range of yarn speeds for such roller may be selected by adjustingthe position of the yarn guide along the roller. Thus, if a point nearthe tip of the conical roller is selected, the speed of the conicalsurface and hence the rate of feed will be much less than if a pointnear the base of the roller is selected.

Theplane surface and the conical roller are preferably urged togetherand more preferably controllably biassed in such a way that the pressurein the nip can be'varied, or if necessary released altogether. Such avariation in nip pressure is desirable in order to render the feeddevice suitable for all types of yarn.

The plane surface of the disc orthe conical roller or both preferablyhave a resilient or friction-imparting surface in order to avoid yarnslippage in the nip. This may be achieved by making the roller fromrubber or similar material, or employing a rubber or other elastomericsleeve on the roller. It is particularly simple and advantageous tocover the surface of the rotating disc with a resilient orfriction-imparting material. The yarn .guide is preferably provided withmeans to set the guide BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is aperspective view of one embodiment of the yarn feed device according tothe invention;

FIG. 2 is a perspective view of another form of the present invention;

FIG. 3 is a vertical sectional view of the device shown in FIG. 2; and

FIG. 4 is an elevational view of a further form of the yarn feedmechanism of the invention.

DESCRIPTION OF THE EMBODIMENTS In the device 10 shown in FIG. I, a disc12 having a flat surface 14 is mounted for rotation about a horizontalaxis and is driven by a belt 16 passing around the periphery of thedisc. The disc may alternatively be driven through a pulley securedcoaxially with the disc as to be more fully described hereinafter.

A conical roller 18 is rotatable about an inclined axis and either theconical surface of the roller 18 or the flat surface 14 of the disc 12or both may be covered with resilient material again as to be more fullydescribed hereinafter. In practice, it is simplest to coat the surface14 of the disc. The roller 18 and the surface 14 of the disc makecontact along a line which is a radius of the disc and in order toensure that there is no slippage between the cone and the disc, the axisof the cone passes through the intersection of the axis of the disc withthe plane of its flat surface 14. The cone is mounted on axle 20 to abracket 22 for free rotation about its axis.

A yarn guide 24 is mounted in a position to feed yarn into the nipbetween the disc 12 and the conical roller 18 and is movable along theline of the nip. For this purpose the guide 24 is carried on a rack 26which slides in the frame structure 28 associated with the bracket 22.The position of the rack is controlled and adjusted by means of a pinionwhich is itself actuated by a knurled knob 30. The yarn guide 24 may bemounted in other ways to secure the desired movement along the nip.

It may not be possible to ensure exact alignment of the axis of the yarnguide tube with the nip and in order to minimize the difficulty theorifice at the end of the tube where the yarn leaves the guide should bedisposed close to the surface 14 of the disc as shown.

In operation the disc 12 is driven at a constant speed by the belt 16moving in the direction of the arrows. Yarn from a supply package (notshown) is threaded through the yarn guide and passes through the nipbetween the disc 12 and the conical roller 18 to the point where a yarnsupply is required, for example the feed point of a weft-knittingmachine.

By reason of the radial direction on the surface 14 of the disc 12 ofthe line of contact with the conical roller 18 the linear speed of thenip surfaces varies uniformly along the line of the nip. A yarn speedappropriate for the knitting operation or for a particular part of theknitting cycle can thus be selected by adjusting the position of theyarn guide 24 along the line of the nip.

Another form of device according to the invention is shown, by way ofexample, in FIGS. 2 and 3.

The frame 40 of the unit 10' carries a slidable vertical rod 42 which ismovable along its own axis. The upper part of the frame 44 carries aninclined, partly threaded rod 46 which is secured to the frame by twonuts 48 and 50. The lower end of the rod 46 carries a cone 52, supportedon two axially spaced, rotary bearings 52a, 52b.

The slidable rod 42 carries a hollow pulley 54, integral with which is ahorizontal flat disc 56. The hollow pulley and disc are supported by twospaced rotary bearings 60a and 60b.

The rod 42 has a washer 62 and a compression spring 64 mounted on it,the washer being located by a pin 66 so that the spring 64 is compressedbetween the washer 62 and the frame 40. This causes the disc 56 to beheld in contact with the cone 52.

The lower end of the rod.42 is slotted, and mounted in the slot is alever 70, secured by a pin 72. Movement of the lever 70 causes theprofiled end 74 to bear against the frame and to draw the rod 42downwards, thus separating the disc 52 from the cone 56.

The unit is driven by means of a belt (not shown) in contact with thepulley 54. Yarn is led between the surface of the disc 56 and the cone52 through a yarn guide 76, the position of which is controlled byrotation of a knurled nut 78 acting on a threaded rod 80 to which theyarn guide is fixed. After passing through the nip between the cone anddisc surface, the yarn is lifted clear of the surface by a second guide82 and thence it is passed to the feeder of the knitting machine (notshown).

The following are the adjustments which can be made to the yarn feedingdevice shown in FIGS. 2 and 3.

Changes to the pressure between the cone 52 and disc 56 can be madeeither by changing the spring 64, by altering the degree of compressionby moving the pin 66, or by inserting additional washers 62 between thespring and the pin.

Correct location of the cone relative to the disc is achieved byadjustment of the positions of the two nuts 48 and 50. The hole in theframe through which the rod 46 passes is preferably made oversize sothat lateral adjustment is also possible.

The contact between the cone 52 and disc 56 depends on the angle at thebend between the upper part 44 and the lower part 44' of the frame 40.If it is found difficult to reproduce this angle in multiple production,either or both of the bearings 52a and 60a may be removed. The play thusintroduced into the mountings of the disc and cone allows them to locateone to the other to form the required linear nip.

A preferred embodiment of our invention is illustrated in FIG. 4. Inthis form of the invention, positive drive means are provided for thedisc or plate so that yarn feed can be brought up to speed or stoppedwithout slippage which slippage, as hereinbefore set forth, oftenresults in yarn breakage. Further, in this form of the invention a morepositive drive between the flat surface of the disc or plate and theactive surface of the cone is provided.

In FIG. 4 the yarn feed device 10" comprises a disc or plate having itsupper surface provided with a resilient rubber-like coating 82. The disc80 is rotated by a pulley 84 provided with a plurality of uniformlyspaced and radially projecting pins or pips 86 which engage openings 88in a drive belt 90. The disc 80 and its connected pulley 84 are mountedfor rotation on a shaft 92 secured to the platform 94.

The assembly also includes a cone 96 which preferably has its conicalsurface roughened such as by sandblasting or otherwise coated with ahigh friction material to insure positive engagement between the conicalsurface and the rubber-like composition 82 on the upper surface of thedisc 80.

The cone 96 is mounted for rotation on a shaft 98 which mounting mayinclude bearings such as shown in FIG. 3 of the drawings. The extendedend of the shaft 98 is threaded as shown and is adjustably mounted tothe upper end 100 of a lever arm 102 by a pair of nuts 104 and 106. Thelever arm 102 is pivotally mounted by a cross shaft or pivot pin 108 toan arm 110, the lower end of which is rigidly secured to the frame 94. Aspring 112 has one end connected, as at 114, to the bracket or arm andthe other end is pin-connected, as at 116, to the lever arm 102 betweenthe pivot shaft 108 and shaft 98 whereby the cone is positivelydepressed onto the surface of the disc 80.

The arm or bracket 110 also has secured thereto, a leaf spring 118, byfastener 120. The leaf spring 118 is formed with a depression 122. Thelever arm 102 has a lower extension 124 which is so positioned relativeto leaf spring 118 and its depression 122 that when it is desired toinactivate the cone 96 and its yarn feed function, lever arm end 124 isdepressed and held in the depressed position by the spring depression122 thus overcoming the force of spring 112.

It will be recognized by those skilled in the art that in view of thepositive drive for the disc or plate 80 it is possible to press the coneat greater force against the disc and since the disc has a deformable orresilient upper surface it will take up any small irregularities inmanufacture of the device and grip the yarn to be fed at any point alongthe nip.

Not shown in FIG. 4 is the adjustable yarn guide which may be configuredas shown in FIGS. 1 or 2 of the drawings.

From the foregoing description of various embodiments of the presentinvention, it will be seen that the yarn feed mechanism fullyaccomplishes the aims and objectives hereinbefore set forth to therebyprovide a simple, relatively cheap, fully speed variable, positive yarnfeeder which may be readily adopted to new or old knitting machines. Itwill also be recognized that various modifications may be made in thefeed device without departing from the scope of the present invention.

We claim:

1. A yarn feed device for knitting and the like textile machinescomprising:

a circular plate having a plane surface;

means supporting said plate for rotation about an axis normal to saidsurface;

at least one conical roller;

a lever supporting said conical roller for rotation about its axis, saidaxis being inclined to and intersecting the axis of rotation of saidsurface and said roller bodily cooperatively engaging said surfaceradially thereof so as to define therewith a nip, the line whereofintersects said axes of rotation of said surface and said conical rollerat the point of intersection of said axes;

drive means for rotating at least one of said plate and said rollerabout said axis thereof;

a yarn guide located in yarn supplying relation to said nip and beingadjustable along the length of said nip and means for so adjusting saidguide whereby said yarn can be given a speed corresponding to the linearspeed of said surface at the point of yarn sup- P y;

means pivotally mounting said lever intermediate its ends on the platesupporting means for pivotal movement about an axis normal to the axisof rotation of the circular plate;

said lever being substantially vertically disposed and having an upperend above the pivotal mount supporting the conical roller for rotatablemovement;

spring means connected between the plate supporting means and the upperportion of the lever above the pivot point for constantly urging saidupper end down toward the plate so as to constantly urge said conicalroller into engagement with the plate; and

a spring latch mounted on and outstanding from the plate supportingmeans and with which the lower portion of the lever below the pivotpoint is adapted to cooperate so as to hold the lever in a lockedposition with the roller out of engagement with the plate.

2. The invention defined in claim 1 wherein the drive means includes apositive drive for rotating said plate.

3. The invention defined in claim 1 wherein said plane surface of saidcircular plate is resilient and the surface of the conical roller isroughened.

1. A yarn feed device for knitting and the like textile machinescomprising: a circular plate having a plane surface; means supportingsaid plate for rotation about an axis normal to said surface; at leastone conical roller; a lever supporting said conical roller for rotationabout its axis, said axis being inclined to and intersecting the axis ofrotation of said surface and said roller bodily cooperatively engagingsaid surface radially thereof so as to define therewith a nip, the linewhereof intersects said axes of rotation of said surface and saidconical roller at the point of intersection of said axes; drive meansfor rotating at least one of said plate and said roller about said axisthereof; a yarn guide located in yarn supplying relation to said nip andbeing adjustable along the length of said nip and means for so adjustingsaid guide whereby said yarn can be given a speed corresponding to thelinear speed of said surface at the point of yarn supply; meanspivotally mounting said lever intermediate its ends on the platesupporting means for pivotal movement about an axis normal to the axisof rotation of the circular plate; said lever being substantiallyvertically disposed and having an upper end above the pivotal mountsupporting the conical roller for rotatable movement; spring meansconnected between the plate supporting means and the upper portion ofthe lever above the pivot point for constantly urging said upper enddown toward the plate so as to constantly urge said conical roller intoengagement with the plate; and a spring latch mounted on and outstandingfrom the plate supporting means and with which the lower portion of thelever below the pivot point is adapted to cooperate so as to hold thelever in a locked position with the roller out of engagement with theplate.
 2. The invention defined in claim 1 wherein the drive meansincludes a positive drive for rotating said plate.
 3. The inventiondefined in claim 1 wherein said plane surface of said circular plate isresilient and the surface of the conical roller is roughened.